HP Cisco MDS 9216 - Fabric Switch Configuration Manual page 430

Buffer Credit Allocation
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
BB_credit buffers for ISL connections can be configured from a minimum of 2 buffers to a
•
maximum of 250 buffers for dedicated rate mode or 16 buffers for shared rate mode.
• BB_credit buffers for Fx port mode connections can be configured. The minimum is 2 buffers and
the maximum of 250 buffers for dedicated rate mode or 16 buffers for shared rate mode.
• Performance buffers are not supported on this module.
Each port group on the 48-port 4-Gbps Fibre Channel switching module consists of 12 ports. The ports
in shared rate mode have bandwidth oversubscription of 4:1 by default. However, some configurations
of the shared ports in a port group can have maximum bandwidth oversubscription of 5:1 (considering
that each port group has 12.8-Gbps bandwidth).
The following example configurations are supported by the 48-port 4-Gbps Fibre Channel switching
modules:
Twelve ports with shared rate mode and 4-Gbps speed (4:1 oversubscription) (default)
•
One port with dedicated rate mode and 4-Gbps speed plus
•
11 ports with shared rate mode and 4-Gbps speed (5:1 oversubscription)
One port with dedicated rate mode and 4-Gbps speed plus
•
11 ports with shared rate mode and 2-Gbps speed (2.5:1 oversubscription)
Two ports with dedicated rate mode and 2-Gbps speed plus
•
10 ports with shared rate mode and 4-Gbps speed (5:1 oversubscription)
Two ports with dedicated rate mode and 2-Gbps speed plus
•
10 ports with shared rate mode and 2-Gbps speed (2.5:1 oversubscription)
• Twelve ports with dedicated rate mode and 1-Gbps speed
Three ports with dedicated rate mode and 4-Gbps speed plus
•
four ports with shared rate mode and 1-Gbps speed plus
five ports put out-of-service (see
Figure 22-3
4-Gbps
Dedicated
4-Gbps
Dedicated
• Six ports with dedicated rate mode and 2-Gbps speed plus
four ports with shared rate mode and 1-Gbps speed plus
two ports put out-of-service (see
Cisco MDS 9000 Family CLI Configuration Guide
22-10
Example Speed and Rate Configuration on a 48-Port 4-Gbps Switching Module
3
1
4-Gbps 1-Gbps
Dedicated Shared
2 4
1-Gbps
1-Gbps
Shared Shared
Chapter 22
Figure 22-3)
5
7
1-Gbps
Out of
Shared
Service
8
6
Out of Out of
Service Service
Figure 22-4)
Configuring Generation 2 Switches and Modules
9 11
Out of
Service
10
12
Out of
Service
OL-16184-01, Cisco MDS SAN-OS Release 3.x